diff --git a/composer.lock b/composer.lock
index 0fa61b2c9f0d4b497886782b338a49c94d799d1a..62ac0d2be5f941c5b3d5a2c8d920c5c8e834d2e9 100644
--- a/composer.lock
+++ b/composer.lock
@@ -531,7 +531,7 @@
         },
         {
             "name": "drupal/core",
-            "version": "9.3.4",
+            "version": "9.3.x-dev",
             "dist": {
                 "type": "path",
                 "url": "core",
@@ -788,7 +788,7 @@
         },
         {
             "name": "drupal/core-project-message",
-            "version": "9.3.4",
+            "version": "9.3.x-dev",
             "dist": {
                 "type": "path",
                 "url": "composer/Plugin/ProjectMessage",
@@ -821,7 +821,7 @@
         },
         {
             "name": "drupal/core-vendor-hardening",
-            "version": "9.3.4",
+            "version": "9.3.x-dev",
             "dist": {
                 "type": "path",
                 "url": "composer/Plugin/VendorHardening",
@@ -7908,7 +7908,11 @@
     ],
     "aliases": [],
     "minimum-stability": "dev",
-    "stability-flags": [],
+    "stability-flags": {
+        "drupal/core": 20,
+        "drupal/core-project-message": 20,
+        "drupal/core-vendor-hardening": 20
+    },
     "prefer-stable": true,
     "prefer-lowest": false,
     "platform": [],
@@ -7916,5 +7920,5 @@
     "platform-overrides": {
         "php": "7.3.0"
     },
-    "plugin-api-version": "2.2.0"
+    "plugin-api-version": "2.1.0"
 }
diff --git a/composer/Metapackage/CoreRecommended/composer.json b/composer/Metapackage/CoreRecommended/composer.json
index ea680d29618721eca56694e49ea69328ddcacf54..1a2f515a4557a6588934d3bbeb9f5b8125d20ce3 100644
--- a/composer/Metapackage/CoreRecommended/composer.json
+++ b/composer/Metapackage/CoreRecommended/composer.json
@@ -7,7 +7,7 @@
         "webflo/drupal-core-strict": "*"
     },
     "require": {
-        "drupal/core": "9.3.4",
+        "drupal/core": "9.3.x-dev",
         "asm89/stack-cors": "1.3.0",
         "composer/semver": "3.2.6",
         "doctrine/annotations": "1.13.2",
diff --git a/composer/Metapackage/PinnedDevDependencies/composer.json b/composer/Metapackage/PinnedDevDependencies/composer.json
index b49851f3419043721cf3a00afa46177abcc4e57a..019a9f5b0bac3b170a2b1ea0c42b9201ae60db80 100644
--- a/composer/Metapackage/PinnedDevDependencies/composer.json
+++ b/composer/Metapackage/PinnedDevDependencies/composer.json
@@ -7,7 +7,7 @@
         "webflo/drupal-core-require-dev": "*"
     },
     "require": {
-        "drupal/core": "9.3.4",
+        "drupal/core": "9.3.x-dev",
         "behat/mink": "v1.9.0",
         "behat/mink-selenium2-driver": "v1.5.0",
         "composer/ca-bundle": "1.3.1",
diff --git a/composer/Template/LegacyProject/composer.json b/composer/Template/LegacyProject/composer.json
index 842fa469e78f4806c84a7e00e002ea8658d6e021..1b1a2af337ab82947aadd8c0bd4a60fa65447a2c 100644
--- a/composer/Template/LegacyProject/composer.json
+++ b/composer/Template/LegacyProject/composer.json
@@ -27,7 +27,7 @@
     "conflict": {
         "drupal/drupal": "*"
     },
-    "minimum-stability": "stable",
+    "minimum-stability": "dev",
     "prefer-stable": true,
     "config": {
         "sort-packages": true
diff --git a/composer/Template/RecommendedProject/composer.json b/composer/Template/RecommendedProject/composer.json
index fcb5ccd621811cde28c38b29bc56279881021de8..99e9f55f239450f5b34d4e885c73f9d6c3b4fc2d 100644
--- a/composer/Template/RecommendedProject/composer.json
+++ b/composer/Template/RecommendedProject/composer.json
@@ -26,7 +26,7 @@
     "conflict": {
         "drupal/drupal": "*"
     },
-    "minimum-stability": "stable",
+    "minimum-stability": "dev",
     "prefer-stable": true,
     "config": {
         "sort-packages": true
diff --git a/core/lib/Drupal.php b/core/lib/Drupal.php
index 2cfe391dd471848bda82bfe04e1afe1fa7788010..66430905cef7360c8617020dfe98dda2ea3a9aad 100644
--- a/core/lib/Drupal.php
+++ b/core/lib/Drupal.php
@@ -75,7 +75,7 @@ class Drupal {
   /**
    * The current system version.
    */
-  const VERSION = '9.3.4';
+  const VERSION = '9.3.5-dev';
 
   /**
    * Core API compatibility.